This invention relates to a lifting apparatus for atmospheric interface devices on a submarine (or submersible), and a submarine (or submersible) comprising the lifting apparatus.
The invention applies generally to the naval (or nautical) sector and, more specifically, to the production of military submarines.
Indeed, during navigation underwater, submarines often need to lift above the surface of the water several atmospheric interface devices, be they for detection (sensors), communication (antennas), observation (periscope) or alternatively air intake (snorkel) to exchange information with the outside or to recharge the batteries
In this text, the term “atmospheric interface” is used to include all the devices just mentioned as well as other similar devices normally used in submarines.
Lifting is normally effected by specific movable mounting units, consisting mostly of lengthwise, faired tubular structures or masts, to which the sensors or antennas devices, driven by specific actuators, are anchored
Traditionally, each sensor (or antenna) is driven by a dedicated lifting apparatus, or by one which is at most shared with another sensor.
Typically, this system consists of a guide, having a closed polygonal cross section, inside which the movable mounting unit slides.
Depending on the type of lifting system, which may be single- double-stage, the movable mounting unit has a different structure and a variable number of components.
In the case of a single-stage lifting system, the movable mounting unit comprises only the faired mast, with the sensor/antenna installed on the top of it.
Alternatively, in the case of a double-stage lifting system, the faired mast (first stage) comprises inside it a slider (second stage) on which the sensor/antenna is installed
That way, the lifting stroke is divided into two half-strokes, one travelled by the mast and one by the slider.
As mentioned above, solutions are also known where two or more sensors/antennas are installed on a single lifting apparatus.
In these solutions, too, however, there is a single faired mast (or first stage) driven by a dedicated actuator to lift both of the sensors.
A double-stage lifting system is also known where the drive of the two (or more) sensors is partly independent, the first stage faired mast) being shared and the second stage, which requires much less powerful and smaller actuators, being independent.
The integration of two or more sensors/antennas using a single first stage, shared by the two or more sensors/antennas is, however, strongly limited by the need to keep their dimensions within relatively restricted limits in order for them to be effectively integrated (without departing from design parameters).
A lifting apparatus of the type described above is described in document EP2076428 in the name of the same Applicant as this invention.
In light of this, no solutions are currently known which allow a plurality of devices (sensors/antennas) of reduced size to be lifted independently.